/*
 *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.
 */

/* globals StreamVisualizer */

'use strict';

const startButton = document.getElementById('startButton');
const callButton = document.getElementById('callButton');
const hangupButton = document.getElementById('hangupButton');
callButton.disabled = true;
hangupButton.disabled = true;
startButton.onclick = start;
callButton.onclick = call;
hangupButton.onclick = hangup;

const canvas = document.querySelector('canvas');

let startTime;
const localVideo = document.getElementById('localVideo');
const remoteVideo = document.getElementById('remoteVideo');

localVideo.addEventListener('loadedmetadata', () => {
  return console.log(`Local video videoWidth: ${this.videoWidth}px,  videoHeight: ${this.videoHeight}px`);
});

remoteVideo.addEventListener('loadedmetadata', () => {
  return console.log(`Remote video videoWidth: ${this.videoWidth}px,  videoHeight: ${this.videoHeight}px`);
});

remoteVideo.addEventListener('resize', () => {
  console.log(`Remote video size changed to ${remoteVideo.videoWidth}x${remoteVideo.videoHeight}`);
  // We'll use the first onsize callback as an indication that video has started
  // playing out.
  if (startTime) {
    const elapsedTime = window.performance.now() - startTime;
    console.log(`Setup time: ${elapsedTime.toFixed(3)}ms`);
    startTime = null;
  }
});

let localStream;
let pc1;
let pc2;
const offerOptions = {
  offerToReceiveAudio: 1,
  offerToReceiveVideo: 1
};

function getName(pc) {
  return (pc === pc1) ? 'pc1' : 'pc2';
}

function getOtherPc(pc) {
  return (pc === pc1) ? pc2 : pc1;
}

function gotStream(stream) {
  console.log('Received local stream');
  localVideo.srcObject = stream;
  localStream = stream;
  callButton.disabled = false;
}

function start() {
  console.log('Requesting local stream');
  startButton.disabled = true;
  navigator.mediaDevices
      .getUserMedia({
        audio: true,
        video: true
      })
      .then(gotStream)
      .catch(e => alert(`getUserMedia() error: ${e.name}`));
}

function call() {
  callButton.disabled = true;
  hangupButton.disabled = false;
  console.log('Starting call');
  startTime = window.performance.now();
  const videoTracks = localStream.getVideoTracks();
  const audioTracks = localStream.getAudioTracks();
  if (videoTracks.length > 0) {
    console.log(`Using video device: ${videoTracks[0].label}`);
  }
  if (audioTracks.length > 0) {
    console.log(`Using audio device: ${audioTracks[0].label}`);
  }
  const servers = null;
  pc1 = new RTCPeerConnection(servers);
  console.log('Created local peer connection object pc1');
  pc1.onicecandidate = e => onIceCandidate(pc1, e);
  pc2 = new RTCPeerConnection(servers);
  console.log('Created remote peer connection object pc2');
  pc2.onicecandidate = e => onIceCandidate(pc2, e);
  pc1.oniceconnectionstatechange = e => onIceStateChange(pc1, e);
  pc2.oniceconnectionstatechange = e => onIceStateChange(pc2, e);
  pc2.ontrack = gotRemoteStream;

  localStream.getTracks().forEach(track => pc1.addTrack(track, localStream));
  console.log('Added local stream to pc1');

  console.log('pc1 createOffer start');
  pc1.createOffer(offerOptions).then(onCreateOfferSuccess, onCreateSessionDescriptionError);
}

function onCreateSessionDescriptionError(error) {
  console.log(`Failed to create session description: ${error.toString()}`);
}

function onCreateOfferSuccess(desc) {
  console.log(`Offer from pc1\n${desc.sdp}`);
  console.log('pc1 setLocalDescription start');
  pc1.setLocalDescription(desc).then(() => onSetLocalSuccess(pc1), onSetSessionDescriptionError);
  console.log('pc2 setRemoteDescription start');
  pc2.setRemoteDescription(desc).then(() => onSetRemoteSuccess(pc2), onSetSessionDescriptionError);
  console.log('pc2 createAnswer start');
  // Since the 'remote' side has no media stream we need
  // to pass in the right constraints in order for it to
  // accept the incoming offer of audio and video.
  pc2.createAnswer().then(onCreateAnswerSuccess, onCreateSessionDescriptionError);
}

function onSetLocalSuccess(pc) {
  console.log(`${getName(pc)} setLocalDescription complete`);
}

function onSetRemoteSuccess(pc) {
  console.log(`${getName(pc)} setRemoteDescription complete`);
}

function onSetSessionDescriptionError(error) {
  console.log(`Failed to set session description: ${error.toString()}`);
}

function gotRemoteStream(e) {
  if (remoteVideo.srcObject !== e.streams[0]) {
    remoteVideo.srcObject = e.streams[0];
    console.log('pc2 received remote stream');
    const streamVisualizer = new StreamVisualizer(e.streams[0], canvas);
    streamVisualizer.start();
  }
}


function onCreateAnswerSuccess(desc) {
  console.log(`Answer from pc2:\n${desc.sdp}`);
  console.log('pc2 setLocalDescription start');
  pc2.setLocalDescription(desc).then(() => onSetLocalSuccess(pc2), onSetSessionDescriptionError);
  console.log('pc1 setRemoteDescription start');
  pc1.setRemoteDescription(desc).then(() => onSetRemoteSuccess(pc1), onSetSessionDescriptionError);
}

function onIceCandidate(pc, event) {
  getOtherPc(pc)
      .addIceCandidate(event.candidate)
      .then(() => onAddIceCandidateSuccess(pc), err => onAddIceCandidateError(pc, err));
  console.log(`${getName(pc)} ICE candidate:\n${event.candidate ? event.candidate.candidate : '(null)'}`);
}

function onAddIceCandidateSuccess(pc) {
  console.log(`${getName(pc)} addIceCandidate success`);
}

function onAddIceCandidateError(pc, error) {
  console.log(`${getName(pc)} failed to add ICE Candidate: ${error.toString()}`);
}

function onIceStateChange(pc, event) {
  if (pc) {
    console.log(`${getName(pc)} ICE state: ${pc.iceConnectionState}`);
    console.log('ICE state change event: ', event);
  }
}

function hangup() {
  console.log('Ending call');
  pc1.close();
  pc2.close();
  pc1 = null;
  pc2 = null;
  hangupButton.disabled = true;
  callButton.disabled = false;
}